I know this never received a reply, but since there is not a lot in searching Google on this subject with Navien heaters, I thought I would share how I handled this situation. I don’t have a Vera system, I use Hubitat, but hopefully Vera supports the equipment I would recommend or a similar dry relay. I have a Navien NPE-210A that was just installed with the Hot Button Kit. This is essential for controlling the recirculation. Yes it is correct that Navien has a closed API for their wireless unit and even hint on their website that they MAY start charging at some point in the future for access to that service. As recirc is the only feature that I would really need on-demand, that seems like overkill, plus I want it tied into my system to be triggered by anything I want (in this case motion sensors in the bathrooms), an on-demand button on the dashboard, and Google Home integration.
So here is how I did it:
Make sure to get the Hot Button Kit installed from Navien…
Purchase a Zigbee or Z-Wave dry relay. This acts like a remote switch but does not supply power to the circuit. I purchased a Zooz Multirelay, from Amazon, that I know would work with Hubitat. According to the box it is also compatible with Vera, but I would verify that. This relay can be powered by the remote power connection on Signal 1 of the hot button controller or a USB-C cable plugged into a 1A power supply.
I hooked the 12V power and GND from the Hot Button Kit to the power inputs for the Zooz MultiRelay. I then connected the two contacts of Switch2 of the Hot Button Kit with the two contacts of one of the three relays on the Zooz MultiRelay. The device will show up as three devices, one for each relay (or a parent and child devices, not sure how it shows up on Vera).
I paired the Zooz MultiRelay with the hub.
I changed the device parameters for the relay that the Hot Button Kit’s Signal2 was connected to to be a momentary push button instead of a toggle switch. This ensures that when triggered, it will only be on for one second then turn off, mimicking the push button that comes with the Hot Button Kit. You only need a short signal to the Hot Button Kit, not a continuous on switch.
Created rules for my motion sensors based upon time of day, etc. At this point it is limitless on 5how you can set triggers for the recirc. I also added the relay switch to be shared with Google Home so it can also be triggered via voice command.
Thanks very much for following up. I probably should have followed up on my post. I got something very similar working using a mimolite as the relay switch. Mine is triggered when I turn the shower light on.